Pure leptonic proposal to $W^{+}{W}^{-}$ excess and neutrino mass generation

Abstract

We investigate the TeV models for neutrino mass generation as candidate models to explain the recent 2$\sigma$ excess of leptonic $W^{+}{W}^{-}$ pair production at LHC. Several models with singly charged exotic states that may explain the excess require light masses completely excluded by LEP experiments. One possible model with new lepton doublets can fit the observation and evade all direct search bounds but with tuned Yukawa structure to satisfy lepton universality. The new exotic leptons $L^{\pm }$ decay into $L^{\pm }\to {\ell }^{\pm }\varphi$ where $\varphi$ is a light singlet scalar of $\mathcal{O}$(MeV) that decays into neutrinos. Drell-Yan production of $L^{+}{L}^{-}\to {\ell }^{+}{\ell }^{-}+{\cancel{E}}_T$ fits the excess and $L^{\pm }{L}^0\to {\ell }^{\pm }+{\cancel{E}}_T$ is completely buried in SM background.